Sequential Ground Motion Effects on the Behavior of a Base-Isolated RCC Building

Table 2

Results for modal analysis.

Mode number	Fixed-base RCC			RCC with isolators
	Frequency (Hz)	Effective mass coefficient		Frequency (Hz)	Effective mass coefficient
		(1)	4.92		77.1%	0	0.49	100%	0
(2)	4.92	0	77.1%	0.49	0	100%
(3)	6.85	0	0	0.56	0	0
(4)	6.86	0	0	5.04	0	0
(5)	8.18	0	0	5.04	0	0
(6)	8.21	0	0	6.95	0	0
(7)	8.72	0	0	6.95	0	0
(8)	8.72	0	0	8.28	0	0
(9)	10.67	0	0	8.32	0	0
(10)	12.74	0	0	8.87	0	0
(11)	12.75	0	0	8.87	0	0
(12)	13.63	0	0	12.98	0	0
(13)	13.64	0	0	12.98	0	0
(14)	14.06	0	0	13.87	0	0
(15)	14.09	0	0	13.88	0	0
(16)	14.34	0	0	14.26	0	0
(17)	15.29	0	0	14.27	0	0
(18)	15.29	0	0	14.56	0	0
(19)	15.59	20.1%	0	15.33	0	0
(20)	15.60	0	20.1%	15.33	0	0
Total		97.1%	97.1%		100%	100%